In the past year, science has achieved a number of major steps forward, from the probable discovery of the elusive Higgs boson, a crucial particle for our understanding of physics, to the landing of NASA's Curiosity Rover on Mars.

In climate science, researchers took a comprehensive look at polar ice loss, discovering with more detail than ever how the Antarctic and Arctic are responding to global warming. Meanwhile, anthropologists traced humanity's roots, unearthing hints of an unknown human ancestor that once lived in China. And then there were the strange-yet-true findings, such as a study suggesting that Korean eunuchs before the 1800s outlived their contemporaries.

But there's always more to wish for. As 2013 begins, LiveScience asked researchers in various fields about their hopes and dreams for the new year. From more-productive discussions about climate change to warnings about new psychiatric diagnoses, here's what these scientists had to say:

Physics

A new subatomic particle discovered this summer is very likely the Higgs boson, which gives mass to all other particles, according to the Standard Model of particle physics. The likely discovery came almost as a disappointment to some physicists, who had hoped the particle would behave unexpectedly, opening doors for new and wild physics theories. [Wacky Physics: The Coolest Little Particles in Nature]

But the Higgs boson isn't the be-all-end-all, said Tara Shears, a physicist at the University of Liverpool. The Standard Model doesn't explain gravity, dark matter or why antimatter behaves differently from regular matter, Shears told LiveScience.

"The next big question for us is to find the deeper understanding that can explain and describe all of this," Shears said, referring to the concepts not explained by the Standard Model. "It's a big question, certainly not one that we will crack next year, but I hope we make some observations that might give us a clue to what that understanding might be."

On Shears' 2013 wish list is something from out of left field, whether it be unusual results from the Higgs or new measurements of matter and antimatter.

"In brief, I'd love to see a definitive measurement made which is at odds with the Standard Model," Shears said. "We haven't had one yet. It's about time it happened."

Climate

The past year saw record heat and ice melt in the Arctic, while Superstorm Sandy triggered talk of global warming's wrath as the storm barreled into the Northeast in October. In other words, it was a big year for climate. [7 Hottest Climate Stories of 2012]

Plenty of questions remain about how severe climate change's effects will be. But to climatologist Claire Parkinson, project scientist for NASA's Aqua mission, next year's challenges aren't so much about the research.

"I think the most important progress needed right now is not progress in the science itself, but progress in being civil in the discussion of the science and relaying the importance of the science," Parkinson told LiveScience.

"The progress I would most like to see would be for scientists and others to stop denouncing people who disagree with them, and instead treat different points of view with respect," while still explaining the science of climate-change consequences, Parkinson said.

And she'd like to see climate get its due as a really cool field.

Scientists should "relay with fascination the role of climate in the 4.5-billion-year evolution of the Earth system, and the exciting and varied ways in which that evolution has been unveiled by scientists over the past 200 years," Parkinson said.

Space

With robots roving over Mars and astronomers spotting new exoplanets in the heavens, it's been a good year for space scientists.

Next year, however, may be the one that scientists find "Earth 2.0," an Earth-sized and potentially habitable exoplanet (a planet outside our Solar System), said Abel Mendez, head of the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo.

But don't pack your spacesuit for a new home planet yet, Mendez warned. "We will be far from sure if it is indeed habitable or even inhabited," he told LiveScience.

Currently, all potentially habitable exoplanets that have been discovered are much larger than Earth, Mendez said, but with the increasing sensitivity of their instruments, scientists can detect smaller and smaller celestial bodies. It will take longer to boost scientific measurements that can tell us about the atmosphere of a planet many light-years away. Without that knowledge, it's difficult to tell if a planet could really support life.

The big goals for 2013, Mendez said, are finding out how frequently Earth-like planets occur and how far they are from Earth.

"We are working on this problem too, so expect answers from various research teams," Mendez said. "Hopefully, they will be similar."

Longevity

Want to be around to ring in 3013? Well, you may not see a magic bullet for longevity in the next year, or in any year. However, recent research has reinforced the notion that lifestyle drives long life, said Michael Joyner, a researcher at the Mayo Clinic who blogs at drmichaeljoyner.com.

Studies aiming to unveil the genetic secrets to a long life span haven't turned up any ace-in-the-hole genes that ensure longer lives, Joyner said. But study after study has reinforced all the advice you've ever heard — to avoid cigarettes, get active, watch your diet and stay engaged in life. [7 Ways to Live Past 100]

"What's new is really what's old," Joyner told LiveScience. Well-off and well-educated people who follow these tried-and-true guidelines will likely push up the number of people who survive past 100 in the future, he said. That could make for a strange world demographically, he added. Forget economic inequality; longevity inequality may be the next big gap.

"I think we're almost heading toward two species of humans. There's going to be the guideline followers who are going to live a long time, and then there are going to be the people who drink too many Big Gulps and are not doing enough and get into a sort of death spiral of chronic disease," Joyner said. "It's crazy."

Mysteries of the mind

Psychologists and psychiatrists look forward to 2013 with some trepidation, thanks to the upcoming publication of the Diagnostic and Statistical Manual of Mental Disorders 5 (DSM-5), the first revision of this so-called "psychiatrist's bible" since 2000.

The last revision saw few changes, but the DSM-5 represents a major overhaul of the book. The manual's changes have important consequences, as the book not only guides psychiatrists and psychologists' diagnoses of mental illness, but also determines which conditions get covered by insurance, disability and other benefits.

In one major change, Asperger's syndrome will disappear, instead subsumed by the broader diagnosis of autism spectrum disorder. Hoarding will become its own disorder, separate from obsessive-compulsive disorder.

Among the most contested of changes is a new diagnosis called disruptive mood dysregulation disorder. Proponents say the diagnosis will help provide help for 6- to-18-year-olds who have explosive temper outbursts three or more times a week. Critics say the new diagnosis will make temper tantrums a mental disorder. [Top 10 Controversial Psychiatric Disorders]

"DSM-5 will benefit the drug companies in their disease-mongering effort to sell pills by convincing normal people they are psychiatrically ill," said Allen Francis, a Duke University psychiatrist who headed the last DSM revision and who has been a major critic of the current effort.

Francis said the field currently over-medicalizes normal issues, while leaving the severely mentally ill out to dry, often untreated or in prison.

"We must return to sane psychiatry," he said.

Frank Farley, a Temple University psychologist and former president of the American Psychological Association, agreed that a significant number of professionals and scholars were skeptical about the science that went into the DSM-5.

"Looking to 2013, an international movement has arisen toward re-conceptualizing diagnosis from the ground up, and I look forward to progress on this important topic," Farley said.

The academic side of psychology must also resolve to shape up in 2013, Farley said. As it stands, the discipline paces a great deal of emphasis on new and sexy findings that get media attention, but are rarely replicated by other researchers, a crucial part of the scientific process. In addition, Farley said, too many studies, particularly those that fail to find statistically significant results, go unpublished, leading to a bias in the literature.

Finally, Farley said, as we leave a year that closed with the deadly mass shooting of 20 elementary-school children and six teachers in Newtown, Conn., psychology should resolve to tackle the problem of violence.

"Piecemeal approaches to the problem of violence aren't working. A NATIONAL coordinated organized collaborative approach is needed, similar to the Manhattan Project of WWII, the Moon Mission of the 1960s … and the more recent Human Genome Project," Farley wrote in an email to LiveScience.

"This proposed National Violence Project would generate the best solutions we have, and outline needed areas of further research," Farley said. "It could be funded by government and the private sector, including foundations, and, certainly given the topic, crowd sourcing. I believe development of such a National Violence Project should be a priority for the human sciences in 2013, and should be a White House-backed endeavor."